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ARS Home » Pacific West Area » Pullman, Washington » Plant Germplasm Introduction and Testing Research » Research » Publications at this Location » Publication #422157
Research Project: Genetic Resource and Information Management for Pulse, Temperate Forage Legume, Oilseed, Vegetable, Grasses, Sugar, Ornamental, and Other Crops

Location: Plant Germplasm Introduction and Testing Research

Title: Genome-wide association study and pathway analysis to dissect the genetic control of stay-green in a Brazilian panel of topical maize inbred lines

Author
item UHDRE, RENAN - Washington State University
item PETERLINI, EDICARLOS - Universidade Estadual De Maringá
item CONTRERAS-SOTO, RODRIGO - O'Higgins University
item SCAPIM, CARLOS - Universidade Estadual De Maringá
item Warburton, Marilyn

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/30/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Under drought stress, many maize plants wilt and yellow, and leaves die, contributing to reduced capacity to photosynthesize. This will lead to a decrease in final grain yield. Some plants resist this, and the leaves stay green and continue to actively photosynthesize. This stay-green trait is a major component of drought resistance in maize and other cereal grains. In this study, we found genes that appear to control the stay-green trait. This information will help breeders and geneticists create new maize cultivars that yield better in the increasingly hot and dry climate that farmers now face.

Technical Abstract: The stay-green trait allows plants to continue to photosynthesize in the face of strong biotic and abiotic stresses and is positively correlated with grain yield in maize (Zea mays L). However, information about inheritance and genes controlling this trait is scarce in tropical maize. This study aimed to identify chromosomal regions and genes associated with stay-green, using genome-wide association study (GWAS). Trait architecture was studied using Single Nucleotide Polymorphism (SNP) markers measured in a panel of inbred maize lines derived from tropical populations, and tying these genes to metabolic pathways and potential stay-green mechanisms. The GWAS studies were carried out in 320 tropical inbred maize lines, which were phenotyped in two environments (FEI_1 and FEI_2) in the 2017/2018 growing season in Maringa, Brazil. The trials were arranged in an alpha-lattice experimental design with three replicates. DNA of each inbred line was sequenced by the Genotyping-by-sequencing (GBS) method that generated a dataset of 350,643 high-quality polymorphic SNPs. 23 significant SNPs (p-value < 0.05) were associated with the stay-green trait from GWAS and 25 candidate genes. Pathway analysis identified 55 associated pathways (p-value < 0.02), highlighting mechanisms related to mannitol biosynthesis, spermidine regulation, jasmonate signaling, hydroxycinnamic acid amides, and cuticular wax biosynthesis to regulate drought stress. Pathway analysis identified more candidate genes than GWAS. These findings provide valuable insights for breeding stay-green and genetically diverse maize inbred lines. Additionally, the identified SNPs can be converted into breeder-friendly molecular marker assays, facilitating the selection of genes associated with the stay-green trait.